Patterns of Inheritance Flashcards
_____________ means identical alleles at a genetic locus
homozygous
___________ means two different alleles at a genetic locus
heterozygous
________ ______________ two different alleles at two different genetic loci (base pairs) in the same gene
compound heterozygote
___________ ____________ means two different alleles at two different genetic loci in different genes
Double heterozygote
____________ is the proportion of individuals with a gene mutation who actually express the disease condition. The probability that a genetic variation (or allele) will yield the phenotype at all.
penetrance
___________ ___________ is the phenomenon of differing clinical features (phenotype) among individuals carrying the same genotype
variable expressivity
____________ effect—high frequency of a gene mutation in a population founded by a small ancestral group
founder effect
(bottle neck effect)
Two most common mutations in Tay sachs in the ____________ gene on chromosome 15
TATC (80%) insertion in exon 11
intron 12 splice site alteration
G269Ser in exon 7
What are Mendel’s 3 laws?
- Law of segregation
- Law of independent assortment
- Law of dominance
Mendelian disorders are ________-gene disorders
single
Chromosomal disorders are less often _________ and usually syndromic
inherited
In autosomal dominant inheritance the dominant gene is located on an _______________ and each child of an affected parent has a __% risk
autosome
50% risk
In autosomal dominant inheritance males and females are affected _____________ and the inheritance pattern is __________ with male to male and female to female inheritance observed
equally
vertical
In _____________ ______________ the phenotype of heterozygous is intermediate between heterozygous and homozygous
incomplete dominance
In co-dominance the contributions of both alleles are visible in the ____________
phenotype
Type of inheritance
AD
Disease and inheritance?
- MVP, aorta dilitation, tall - arachnodactyly, scoliosis, lens dislocation and myopia
Marfans -FBN1 gene chromosome 15
autosomal dominant
_________ criteria for diagnosing Marfan syndrome
Ghent
Inheritance pattern?
AR
In autosomal recessive disorders the carrier parents have a _______% chance of having an affected child. Females and males are affected equally. If both parents affected then _____% offspring are affected
25%
100%
In autosomal recessive enzymatic diseases the phenotype can be the result of precursor __________ or the ___________ of product
accumulation
absence
Type of inheritance?
XR
In ________ -_________ ___________ inheritance affected individuals are primarily male with unaffected parents. All female siblings will be carriers and the male offspring of the proband are affected
X-linked recessive
Is X-linked inheritance vertical or horizontal?
Neither horizontal or vertical
Type of inheritance for the following diseases:
Hemophilia A, Duchenne/Becker, Fabry’s, Fragile X, spinobulbar muscular atrophy and Lesch-Nyhan syndrome
X-linked recessive
Type of inheritance for Duchenne/Becker
X-linked recessive
Type of inheritance for Hemophilia A
X-linked recessive
Type of inheritance for Fabry’s
X-linked recessive
Type of inheritance for Fragile X
X-linked recessive
Type of inheritance for spinobulbar muscular atrophy
X-linked recessive
Type of inheritance for Lesch-Nyhan syndrome
X-linked recessive
In _______-__________ ____________ inheritance all female offspring of affected males will carry the mutation (may or may not express the phenotype). No male offspring of affected males will be affected. An affected female has a 50% chance of having an affected child. Nearly all affected individuals have an affected parents.
X-linked dominant
Type of inheritance?
X-linked dominant
Type of inheritance?
X-linked dominant with male lethality
In _____-__________ inheritance only males are affected and there is only male to male transmission with 100% of male offspring from affected parent
Y-linked
Type of inheritance?
Y-linked
The ______________ regions on the Y chromosome are responsible for Y-linked inheritance
pseudoautosomal (PAR)
_____________ inheritance pattern is where female proband has all affected children but male proband has no affected children
mitochondrial
Type of inheritance?
mitochondrial
Heteroplasmy and homoplasmy are affected by _________ segregation
chance
Type of inheritance for the following diseases: LHON, Kearns-Sayre, MELAS, MERRF
mitochondrial
Amish, Mennonite and Hutterite communities have founder mutations for _____________ gene and 80 other disorders
glutaric acidemia (GA1)
French Canadiens (28 disorders) have founder effects in ___________ syndrome and ___________ type I
Leigh syndrome
Tyrosinemia type I
Which disorders should be considered when inheritance is linked through the female line?
XLD, XLR and mitochondrial
Mendelian law of _____________ is violated by uniparental disomy
segregation
Mendelian law of _______ ____________ is violated by genes closely linked on the same chromosome
independent assortment
Mendelian law of _____________ is violated by co-dominance and incomplete dominance
dominance
Type of inheritance?
XLR
Type of inheritance?
XLR with homozygous mom
Type of inheritance?
AD
Type of inheritance?
YL
Type of inheritance?
XLR
Type of inheritance?
AD
Type of inheritance?
AR
For the sequence below, where the capital letters are an exon and the lower case letters are intronic, identify the canonical splice acceptor and splice donor site:
t t t a t t t c c a g T T G A A T C T T T C T G T A A C G T T A A C T G C T T C C A G g t a a g c c t g
gtag
GU 5 splice donor
AG 3 splice acceptor
If the highlighted T* is c.151, write the HGVS nomenclature if the bolded and underlined G** is changed to an A:
t t t a t t t c c a g T* T G** A A T C T T T C T G T A A C G T T A A C T G C T T C C A G g t a a g c c t g
c.153G>A
If the highlighted T is c.151, write the HGVS nomenclature if the bolded and underlined base pairs** are deleted:
t t t a t t t c c a g T T G *A A T C T T T C T G T A A C G T T A A C T G C T T C C A G g t a a g c c t g
c. 154_156delAAT
or c. 154_156del
If the highlighted T is c.151, write the HGVS nomenclature if 3 base pairs, “A-C-T” are inserted between the bolded and underlined base pairs:
t t t a t t t c c a g T T G A A T C ***T T T C T G T A A C G T T A A C T G C T T C C A G g t a a g c c t g
c. 157insACT
If the highlighted T is c.151, write the HGVS nomenclature if the bolded and underlined base pairs are inverted:
t t t a t t t c c a g T T G *A A T** C T T T C T G T A A C G T T A A C T G C T T C C A G g t a a g c c t g
c.154_156inv
or c.154_156invATT
